amount of the material that you observed in the
center graduated cylinder.
3.
Go to the two corresponding pans. Starting from
the outer edge, measure the distance between
left pan, across the center pan, to the outer edge
of the right pan, and record the measurement.
Record the effective spreading width here:
.
Preparing the Calibration Course for
Calculating the Application Rate
1.
Determine a course length by dividing 93 m
2
(1,000 ft
2
) by the effective spread width that
you determined in
Spreading Width (page 27)
; use the course
length formula.
Record the course length
here:
.
Calibration Course Length Formula
Formula
93 m
2
(1,000 ft
2
)
/ Effective width
measurement
=
Calibration course
length
Example
93 m
2
(1,000 ft
2
)
/ 1.8 m (6 ft)
=
51 m (167 ft)
Note:
In this example the effective width
measures 1.8 m (6 ft).
2.
Measure and visibly mark the course length.
Ensure that you allow enough distance before
the starting marker so that the spreader moving
forward at full speed when crossing the first
mark of the course.
Calculating the Application Rate
1.
Determine the area and amount of material that
you are applying to the job site and record those
amounts in the area and materials worksheet.
Record the job site area here:
.
Record the amount of job site material here:
.
2.
Initially, use the recommended application rate
indicated in the
Spreading Charts (page 30)
section or use the rate recommended listed on
the product manufacturer’s label as a guide to
help determine the amount of material that you
would spread over a 93 m
2
(1,000 ft
2
) area.
Note:
In this example the calibration course is
1.8 m (6 ft) by 51m (167 ft).
3.
Set the appropriate drop-rate cam setting; refer
to the
Spreading Charts (page 30)
as a starting
point.
4.
Add material to the hopper.
Note:
In this example we added 11.3 kg (25
lb) of material.
5.
Drive the spreader over the calibration course
while applying the material.
6.
Empty the remaining material of the hopper into
a clean bucket.
7.
Weigh the bucket containing the material and
record the weight. Pour the contents back
into the hopper and then weigh the empty
bucket. Calculate the remaining material weight
using the remaining material weight formula.
Record the remaining material weight here:
.
Remaining Material Weight Formula
Formula
(Remaining
material and
bucket weight) -
(Bucket weight)
= Remaining material
weight
Example
10 kg (22 lb) -
1 kg (2 lb)
=
9 kg (20 lb)
Note:
In this example, 9 kg (20 lb) of material
remain in the hopper after applying the material
to the test course.
8.
Calculate applies material weigh using
the applied material formula that follows.
Record the applied material weight here:
.
Applied Material Weight Formula
Formula
(Original
material weight)
- (Remaining
material weight)
=
Applied material
weight
Example
11.3 kg (25 lb)
- 9 kg (20 lb)
3
=
2.3 kg (5 lb)
Note:
This calculation means that at the
selected motor-rotation speed, 2.3 kg (5 lb) of
material was applied to the 93 m
2
(1,000 ft
2
) test
course.
9.
If necessary, adjust the drop-rate cam to achieve
the recommended application rate. Once you
achieve the correct application rate, repeat
this procedure an additional time to verify your
results.
Important:
Designate a new calibration
course each time, so that the turf is not
damaged by excessive application of
material.
28
